Shutdown system for oil burners



Jan. 17, 1950 R. B. PLAsS 2,494,778

SHUTDOWN SYSTEM FOR OIL BURNERS Filed Jan. 28, 1946 INVENTOR. RA yMo/vo PL 4 ss A7' TRNEV Patented Jan. 17, `1950 2,494,778 SHUTDOWN SYSTEM FOR OIL BURNERS Raymond B. Plass,

Ray Oil Burner Co., S corporation of Delawar Berkeley, Calif., assignor to an Francisco, Calif., a e

Application January 2s, 1946,-seria1Na. 643,395

1 Claim. 1

This invention relates to oil burners of the type used in furnaces or the like wherein oil is pumped to a burner tip, mixed with air, and ignited. In oil burners of this kind, an oil shutoi valve is customarily positioned at some distance from the burner tip. When the burner is shut down, this valve is closed to discontinue the flow of oil to the burner tip. Oil, however, remains in the pipe which leads from the shut-off valve to the burner and also in the burner fuel tube which forms a continuation of said pipe and communicates with the burner tip.

This oil remaining in the pipe and fuel tube gives rise to certain undesirable results. For example, the oil may bleed or drip through the burner tip into the fire box of the furnace. In the fire box, it may burn or partially burn producing a gummy residue which fouls the nozzle and atomizing tube of the burner and prevents the burner from functioning properly. This is quite a 4common occurrence because `after the furnace is shut down, the radiant heat from the iire box causes sufficient heating of oil standing in the adjacent pipe to cause it to expand and to be exuded through the burner tip. In some cases heavy or viscous oils have to be preheated before they will operate satisfactorily in a burner. If such oil is permitted-to remain in the burner tube during a shut down it becomes cold and interferes with proper starting of the burner.

Another disadvantage of oil remaining in the pipe between the shut-ofi' valve and the burner tip arises from the fact that air is supplied at or adjacent the burner tip by a blower driven by a motor which also drives the pump which delivers oil to the burner tip. Consequently, when the motor is energized, oil is instantly delivered through the burner tip but the blower requires a few seconds to obtain its normal operating speed. As a result, oil is fed into the i'lre box before an adequate supply of air is ob tained, ignition is delayed, and when the fuel finally ignites, the excess of oil causes a flareback or burst of flame which is undesirable. It is therefore an object of the present invention to overcome the dinculties related above as well as other diiflculties, and to provide an oil burner with means for automatically removing oilA from the burner tube and oil pipe adjacent such tube whenever the burner is shut down. It

(Cl. 15S- 363) is also an object of the invention to provide means for forcibly withdrawing oil from a burner tube when a burner is shut down, and to provide means whereby the burner oil delivery pump will effect such forcible Withdrawal of oil.

Still further objects and advantages of the invention are made apparent in the following specication in which reference is made to the accompanying drawings which illustrate one form which the invention may assume.

In the drawings:

Fig. 1 is a diagrammatic view illustrating an oil burner and supply means therefore embodying the present invention;

Fig. 2 is an enlarged sectional view illustrating the details of construction of a valve which forms a part of the burner system illustrated in Fig. 1; and

Fig. 3 is a view similar to Fig. 1 but illustrating the application of. the present invention to a slightly different form of burner system.

Referring iirst to Fig. 1 of the drawings, an oil burner system is schematically disclosed as comprising 'a burner tip II) adapted to be disposed within the fire box of a furnace or the like. Oil for the burner is supplied through a pipe I I which communicates with a storage tank or a source of supply not shown, and from which oil is drawn by a pump I2 for delivery into a reservoir I3.

An overflow or return line I4 is customarily provided for the purpose of returning any excess of oil to the source of supply. A pump I5 which, like the pump I2, may be disposed within thereservoir, withdraws oil from the reservoir and delivers it through pipe I6 to a visicosity valve Il. This viscosity valve I'I, the use of which is well known in the art and which may be of the kind disclosed in the patent to Neubauer No. 2,037,994, functions to direct a certain proportion of the oil delivered to it to the burner tip and to direct the remainder of the oil through a return line I8 to the reservoir I3.

The oil which passes through the burner tip flows through a pipe I9, shut-off valve 20 which may be of the magnetically actuated type and pipe 2l which communicates with the fuel tube of the burner. It is customary also to pro-` videa. regulating valve 22 by means of which some of the oil in the viscosity valve may be relieved back to the reservoir I3 to regulate the size of the flame at the burner tip.

A relief valve 23 may also be provided in the event that excessive pressure is built up in the viscosity valve. The valves 22 and 23 are, however, conventional and do not form a part of the present invention.

In the operation of the system disclosed in Fig. l, the pumps l2 and l5 are driven by a single motor, not shown, energized by a circuit which also includes the magnetic. valve 20. Either the same motor or a separate one energized by the same circuit may be employed to operate a blower, to the nozzle tip I6. The valve 20 is normally closed but when the circuit is closed to actuate the pumps this valve is opened by its electro.- magnet energized by the circuit in a conventional manner. Therefore, with the pumps I2 and I5 in operation, oil is drawn through the pipe II, through a valve 25, the construction of which will presently be described, and thro-ugh a pipe 2E communicating between the valve 25 and the pump, I2. The oil thus delivered to the reservoir I3. is picked up by the pump i5 and delivered through pipe I6 through the viscosity valve Il, pipe I9, valve 23 and pipe 2i to the nozzle tip.

When the burner is shut down by opening the `circuit to the motor which drives the pumps, the valve 2b returns to its normal closed position and, except for the present invention, the pipe 2| and fuel tube in burner tip Ill remain filled with oil which causes the difficulties hereinabove described. After the motor is de-energized, however, it coasts or continues to drive the pumps I2 and I5 for several revolutions and this coasting action of the pumps is employed to withdraw the oil from the pipe 2l and the burner tube. This is accomplished through the Valve 25 which, as shown in Fig. A,2, comprises a, housing with a cylindrical chamber 28 in one end within which is reciprocably mounted a piston valve 2.9 having a stem 33 and a poppet valve 3i carriedY thereby. The poppet valve 3'! normally closes a valve port 32 in a wall 33 which separates the cylinder 28 from a spring chamber 34 formed in the end of the valve housing 25 opposite to the cylindrical chamberV 23. A spring 36 in the chamber 34 seats at one end against a seat member 3i' which bears against the valve, and at its otherA end against a cap 38` which forms a closure for the spring chamber 34.

Under normal operating conditions, the spring 36 holds the poppet valve 3l closed so that oil flowing through pipe I I which is connected with a threaded boss Ila on the valve 25' flows into and through the cylindrical chamber 28 passing out through pipe 26 which is connected with a threaded boss 26a. When the motor which energizes the pumps is de-energized the valve 2U lcloses and the pressure resulting from the con'- tinued or coastingaction of the pumps is transmitted througha line 40 which communicates between the line I9 and the valve 25, and enters the valve through an inlet 40a, communicating with the interior of the cylinder 28 at a point which causes the piston 23 to slide in opposition to the pressure of the spring 36. This movement ofthe piston 28, of course, effects opening of the poppet valve 3l and at. the same time effects closing of the port in the cylinder with which the pipe I'I is connected. Consequently, the suction line 26 ofthe pump I2 is in communication through the open poppet valve 3l with the spring chamber not shown, which delivers air (iii 34 and a line 42 forms a communication between the spring chamber 34 and the pipe 2l which communicates with the nozzle tip I0. This line connects with the cap 38 of the spring chamber through the medium of a threaded port 42a therein. Consequently, the coasting action of the pump I2 serves to withdraw oil from the pipe 2|, and the fuel tube of the burner tip I0 and to deliver such oil through the spring chamber 34, the open poppet valve 3| and back through the line 26 into the reservoir I3 so that whenever the. burner is shut down by theV energization of the motor which operates it, all. oil is automatically evacuated from the line between the valve 2lil and the burner tip. A conventional check valve 43 is preferably provided in the line 42 in` order Yto prevent reversal of flow therein.

Fig. 3 shows the application of the present invention to a somewhat simpler type of burner system wherein the reservoir I3 is omitted and a single pump 45 delivers oil through a line 46, magnetic shut-oif valve 4-1 and pipe 48 to the burner tip l0. In this system the viscosity valve I1 is also omitted and a conventional burner regulating valve 49 is employed in the pipe 48. A relief valve 5s is provided in the line 5I which communicates with the line 4:6 anda by-pass line 52 communicates between the'line'5 I4 and the piston end of the valve 25. The pump-45`normally withdraws oil from a source not shown through the pipe' II, valve 25'and pipe 26 whichare identical with the correspondingly numbered parts in Fig. l as areY the line 42 andV check valve 43; Therefore, inV this simplified system de-energization of the motor which is driving the pump 4'5- also-permits themagnetic shut-off valve 41v to close: The coasting action ofthe pump then builds uppres'- sure in the line 45 which is communicated throughlines 5I and 52 tothe valve 25t'0 urge the piston thereinY to the position illustrated in Fig. 3 where it closes the line I I and effects opening of the poppet valve 3| which controls the' line 42.V Oil in the line 48 is then withdrawn and returned? by the pump into' the line ,46' and any excessive pressure in the line 46 resulting from this action will be relieved through' the relief valve 5c vand returned through a line 60 to the source of supply.

In either of the systems shown in Fig. 1 or Fig. 3 whenthe. pump comes to a stop the pressure in the line 40 (Fig. l). or 52 (Fig. 3) drops and the spring` 360i the valve 25 returns the piston to its normal operatingV position.

I claim:

In an oil burner which includes au burner tip, motor driven pump meansfor directing oil from a source of supply to the tip, a conduit from the pump kmeans tothe tip, and a Valve iny saidconduit arrangedv to be closedy upon deenergization of: the motor, a first fuel passage between the source. of supply and the intake of` thel pumpr` means, a second iuelpassage between vthe burner tipand. the intake of the pump means, a pressure actuated valve normallyI opening the. first. Afuel passageand. closing the secondfuel passage and operable by pressure to close the firstfuel passage and openthe second one, a pressure linefor com- Inunicating valve actuating pressure from said conduitfat a point between the pump means and the first named valve tol said pressure actuated valve whereby upon. deenergization ofY the. motor. the. lattervalve will be operated. to openv communication between the intakeV of theV pump` means4 andthe burner tip and theV coastingaction of the pump will withdraw oil from the burner tip,

and means for discharging oil pumped during Number said coasting action toward the source of supply. 1,731,806 RAYMOND B. PLASS. 1,782,668 1,858,302 REFERENCES CITED 5 1,399,395 The following references are of record in the 210371994 file of this patent: 2,210,852

UNITED STATES PATENTS Number Name Date 10 Number 1,431,054 stockstrom 001.3,1922 14,234

Name Date Aldrich Oct. 1.5, 1929 Stuart Nov. 25, 1930 Marshall May 17, 1932 Ray Feb. 28, 1933 Neubauer Apr. 21, 1936 Falkenberg Aug. y6, 1940 FOREIGN PATENTS Country Date Australia July 4, 1928 

